1. Technical Field
Embodiments relate to temperature sensors.
2. Related Art
With the development of increasingly higher performance electronic systems, such as for example personal computers and communication systems, in the electronics industry, the demand for relatively faster memory devices with higher integration characteristics are on the rise. An example of such a memory device is a dynamic random access memory device (DRAM). When semiconductor devices, such as the DRAM devices, are used in cellular phones and notebook computers, the semiconductor devices are often designed to have relatively low power consumption characteristics. Efforts have been directed towards reducing the operating current and the standby current of the semiconductor devices.
The data retention characteristic of DRAM cells including a single transistor and a single storage capacitor may be relatively sensitive to variations in temperature. In many cases, the operating conditions of the internal circuit blocks in a semiconductor integrated circuit may be adjusted based on variations in circumferential temperatures. For example, DRAM devices employed in mobile systems may be designed to adjust a refresh cycle time according to variations in the circumferential temperature. Temperature sensors, such as digital temperature sensor regulators (DTSRs) and analog temperature sensor regulators (ATSRs), are often used to adjust the operating conditions of semiconductor devices, such as DRAM devices, in response to variations in circumferential temperatures. Temperature sensors may detect a relatively high temperature and the operation cycle time may be adjusted to reduce power consumption in a self-refresh mode. The temperature sensors may monitor circumferential temperatures in a normal operation mode.